Electric discharge tube



c. BOL. 1,916,4C8

ELECTRIC DISCHARGE TUBE Filed Feb. 18, 1928 INVENTOR comsus BOL BY (9/ M ,Qdmm

ATT RNEY raphy.

Patented duly 4, 1933 CORNELIS 301:, GP EINDHOVEN, NETEEBLANDQ, ASSIGNQR TO RADIU GQIEtlPOMTION 0F MERICA, A GOREOEATIOET 0K DEEAWABE ELECTRIC DISCHARGE TUBE Application filed February 18, 1928, Serial No. 55,211, and. in the Netherlands April 18, 1927.

The invention relates to electric discharge tubes, more particularly to those for use in installations for wireless telephony and teleg- In the case of vacuum tubes it is known to mount the oscillation generator and the am- I plifier in a common vacuum. In such a system one single filament is utilized for the generator and the amplifier.

The discharge tube according to the invention comprises a plurality of mutually separated sets of grids with anodes pertaining thereto and a common equipotential cathode. The varioussystems are separted from one another by screening walls in order to prevent reaction of one system on another.

In addition to other advantages the use of an equipotential cathode afiords with relation to the filament the further advantagethat when use is made of a hollow cathode with a heating element, this combination can be used as a rectifier. This rectifier may then be used, for example, in anode voltage supply apparatus.

The invention will be more clearly understood by referring to the accompanying drawing which diagrammatically represents a discharge tube according to the invention. In the drawing, several electrode systems are mounted ina glass envelope 1. An equipotential cathode 2 which, according to this mode of execution, consists of a hollow tube which can be heated by radiation or by electron bombardment or in both imannersby means of a heating element 3. The outer surface of the tube is coated with a suitable material, for example, barium oxide.

shields which separate the various systems from one another. The combination of the filament 3 with the hollow tube 2 is very suitable for use as a rectifier.

The electrode systems may be constructed as diflerent stages in a receiving circuit-ar rangement for wireless telegraphy or telephony, but it is also possible to use them in series-connection.

What I claim is:

1. An electron discharge tube comprising an envelope having mounted therein a single tubular cathode, a single heating element within the cathode, a plurality of sets of electrodes, each-set comprising an independent pair of concentric cylindrical input and output electrodes surrounding and coaxial with said cathode and disposed end to end along said cathode to cooperate with distinct and separate lengths of said cathode, and a shielding disk between adjacent sets and extending from the envelope to the cathode.

2. An electron discharge tube comprising to the cathode.

CORNELIS BOL. 

